hi, dan. >> reporter: yeah, hi, jenna. since 9/11 the f.b.i. has conducted well over one hundred of these terrorism-related sting operations. in almost ever case the defense claims entrapment. that defense has not worked a single time yet. hraoelg experts say because the bar is so high. in this case the evidence against mohammed mohammed appears very strong. his father contacted the tprao*eub worried mohammed was becoming rad dhaka hraoeuzed. he had written about jihad and becoming a mart you are. but the defense argues he was young, impressionable and during the elaborate f.b.i. sting operation groomed to be a would be killer. it's a risky defense. >> they need to so something else entirely, andt their client was not the least bit predisposed to want to do that at all, and proving that is actually very difficult under these kind of circumstances. >> reporter: the defense admits mohammed hit numbers on a cellphone thinking it would detonate a massive bomb in a van right in the middle of a holiday tree lighting ceremony here in downtown portland